Collision avoidance

Abstract

A system for warning of potential collisions among subjects includes devices configured to be transported by the subjects. At least one of the devices may have a device identifier and may include a transceiver configured to transmit radio frequency signals including the device identifier. At least one of the devices may include a processor operably connected to a transceiver configured to receive radio frequency signals. In at least one of the devices, the processor is configured to store another device's identifier in a storage medium, to determine a signal strength of a radio frequency signal received from the other device, and to issue a warning signal based at least in part on at least one of the signal strength and the other device's identifier. The warning signal is configured to warn a subject of a potential collision with another subject.

1 . A system for warning of potential collisions among a plurality of subjects, the system comprising:
 a plurality of devices including at least:
 a first device configured to be transported by a first subject, where the first device has a first device identifier, and where the first device includes:
 a first transceiver configured to transmit a first radio frequency signal including the first device identifier, 
 at least one antenna operably connected to the first transceiver, 
 a first processor operably connected to the first transceiver, and 
 a first storage medium operably connected to the first processor; and 
 
 a second device configured to be transported by a second subject, where the second device has a second device identifier, and where the second device includes:
 a second transceiver configured to transmit a second radio frequency signal including the second device identifier, 
 a second processor operably connected to the second transceiver, and 
 a second storage medium operably connected to the second processor; 
 
   where the first transceiver is configured to receive radio frequency signals including the second radio frequency signal, where the first processor is configured to store the second device identifier in the first storage medium, where the first processor is configured to determine a second signal strength of the received second radio frequency signal, and where the first processor is configured to issue a first warning signal based at least in part on at least one of the second signal strength and the second device identifier, where the first warning signal is configured to warn the first subject of a potential collision between the first subject and the second subject; and   where the second transceiver is configured to receive radio frequency signals including the first radio frequency signal, and where the second processor is configured to store the first device identifier in the second storage medium, where the second processor is configured to determine a first signal strength of the received first radio frequency signal.   
     
     
         2 . The system of  claim 1 , where the second processor is further configured to issue a second warning signal based at least in part on at least one of the first signal strength and the first device identifier, and where the second warning signal is configured to warn the second subject of the potential collision between the first subject and the second subject. 
     
     
         3 . The system of  claim 2 ,
 where the second device identifier is at least one of a second device ID and a second device type,   where the first processor is configured to issue the first warning signal based at least in part on the second signal strength and at least one of the second device ID and the second device type by comparing the second signal strength to a second preprogrammed threshold corresponding to the at least one of the second device ID and the second device type,   where the second preprogrammed threshold substantially corresponds to a first distance between the first device and the second device,   where the first device identifier is at least one of a first device ID and a first device type,   where the second processor is configured to issue the second warning signal based at least in part on the first signal strength and at least one of the first device ID and the first device type by comparing the first signal strength to a first preprogrammed threshold corresponding to at least one of the first device ID and the first device type, and   where the first preprogrammed threshold substantially corresponds to a second distance between the first device and the second device.   
     
     
         4 . The system of  claim 3 , where the first preprogrammed threshold and the second preprogrammed threshold are programmable via a wireless link between a programming device and the corresponding device from the first device and the second device. 
     
     
         5 . The system of  claim 1 , where the first subject and the second subject are selected from the group consisting of:
 a person;   a hardhat;   a vehicle;   an intersection; and   a crane.   
     
     
         6 . The system of  claim 1 , where the second device is a member of a group, and the first processor is configured to issue the first warning signal based at least in part on the second device membership in the group. 
     
     
         7 . The system of  claim 1 , where the plurality of devices further comprises:
 a third device configured to be transported by a third subject, where the third device has a third device identifier, and where the third device includes:
 a third transceiver configured to transmit a third radio frequency signal including the third device identifier, 
 a third processor operably connected to the third transceiver, and 
 a third storage medium operably connected to the third processor; 
   where the third transceiver is configured to receive radio frequency signals including the first radio frequency signal and the second radio frequency signal,   where the third processor is configured to store the first device identifier and the second device identifier in the third storage medium,   where the third processor is configured to determine a third signal strength of the received first radio frequency signal,   where the third processor is configured to determine a fourth signal strength of the received second radio frequency signal,   where the third processor is configured to issue a third warning signal based at least in part on at least one of the third signal strength and the first device identifier, where the third signal strength substantially corresponds to a third distance between the first device and the third device; and   where the third processor is configured to issue a fourth warning signal based at least in part on at least one of the fourth signal strength and the second device identifier, where the third signal strength substantially corresponds to a fourth distance between the second device and the third device.   
     
     
         8 . The system of  claim 1 , where the first transceiver is configured to transmit the first radio frequency signal at least one of several times per second and approximately 300 feet. 
     
     
         9 . The system of  claim 1 , where the first warning signal manifests in a form selected from the group consisting of:
 a light,   a flashing light,   a vibration, and   a sound.   
     
     
         10 . The system of  claim 1 , where an antenna power setting of the at least one antenna is programmable. 
     
     
         11 . The system of  claim 1 , where the first device further comprises:
 at least two antennas operably connected to the first transceiver, where the at least two antennas are configured to attach to the first subject such that the second signal strength of the received second radio frequency signal has at least two components, one component for each of the at least two antennas, and where the first processor is configured to substantially determine the incoming direction of the received second radio frequency signal based at least in part on the at least two components.   
     
     
         12 . The system of  claim 1 , where the first device further comprises:
 at least four antennas operably connected to the first transceiver, where the at least four antennas are configured to attach to the first subject such that the second signal strength of the received second radio frequency signal has at least four components, one component for each of the at least four antennas, and where the first processor is configured to substantially determine the incoming direction of the received second radio frequency signal based at least in part on the at least four components.   
     
     
         13 . The system of  claim 1 , where the first storage medium includes a first database configured to store historical data. 
     
     
         14 . The system of  claim 1 , where the first processor is configured to determine the second signal strength by continuously sampling a signal strength indication of the second signal, calculating a running average of the signal strength indication and removing outliers samples of the signal strength indication. 
     
     
         15 . The system of  claim 1 , where the second radio frequency signal further includes data representing a second radio profile describing characteristics of the second transceiver including radio broadcast power, antenna characteristics and transmission signal strength; and
 where the first processor is configured to determine the first distance between the first device and the second device based at least in part on the second signal strength and the second radio profile.   
     
     
         16 . An apparatus configured to warn of a potential collision between a first subject and a second subject, the apparatus comprising:
 a transceiver;   a processor operably connected to the transceiver,
 where the processor is configured to cause the transceiver to transmit an outgoing signal comprising a device identifier, 
 where the processor is further configured to receive from the transceiver incoming signals including
 a first incoming signal transmitted by a first apparatus, where the first incoming signal comprises a first device identifier, and 
 a second incoming signal transmitted by a second apparatus, where the second incoming signal comprises a second device identifier, 
 
 where the processor is configured to determine a first signal strength of the first incoming signal; 
 where the processor is configured to determine a second signal strength of the second incoming signal; 
 where the processor is further configured to issue a warning signal based at least in part on at least one of:
 (a) the first signal strength and the first device identifier, 
 (b) the second signal strength and the second device identifier, and 
 (c) the first signal strength, the first device identifier, the second signal strength and the second device identifier; and 
 
 where the processor is further configured to compare the first signal strength to a preprogrammed threshold and issue the warning signal based at least in part on whether the first signal strength exceeds the preprogrammed threshold. 
   
     
     
         17 . The apparatus of  claim 16 , where the device identifier correlates to a set of preprogrammed threshold distances between the apparatus and other apparatuses, where the first device identifier correlates to a first set of preprogrammed threshold distances between the first apparatus and other apparatuses, and where the second device identifier correlates to a second set of preprogrammed threshold distances between the second apparatus and other apparatuses.